diff --git a/poulpy-core/src/encryption/compressed/gglwe_atk.rs b/poulpy-core/src/encryption/compressed/gglwe_atk.rs
index f0afcae..1ee58a6 100644
--- a/poulpy-core/src/encryption/compressed/gglwe_atk.rs
+++ b/poulpy-core/src/encryption/compressed/gglwe_atk.rs
@@ -1,10 +1,11 @@
 use poulpy_hal::{
-    api::{ScratchAvailable, SvpPPolBytesOf, VecZnxAutomorphism, VecZnxDftBytesOf, VecZnxNormalizeTmpBytes},
+    api::{ModuleN, ScratchAvailable, ScratchTakeBasic, SvpPPolAlloc, SvpPPolBytesOf, VecZnxAutomorphism, VecZnxDftBytesOf, VecZnxNormalizeTmpBytes},
     layouts::{Backend, DataMut, DataRef, Module, Scratch},
     source::Source,
 };
 
 use crate::{
+    ScratchTakeCore,
     encryption::compressed::gglwe_ksk::GGLWEKeyCompressedEncryptSk,
     layouts::{
         GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, LWEInfos,
@@ -16,10 +17,10 @@ impl AutomorphismKeyCompressed<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolBytesOf,
+        Module<B>: ModuleN + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolBytesOf,
     {
         assert_eq!(module.n() as u32, infos.n());
-        GLWESwitchingKeyCompressed::encrypt_sk_tmp_bytes(module, infos) + GLWESecret::bytes_of(infos.n(), infos.rank_out())
+        GLWESwitchingKeyCompressed::encrypt_sk_tmp_bytes(module, infos) + GLWESecret::bytes_of(module, infos.rank_out())
     }
 }
 
@@ -39,8 +40,14 @@ pub trait GGLWEAutomorphismKeyCompressedEncryptSk<B: Backend> {
 
 impl<B: Backend> GGLWEAutomorphismKeyCompressedEncryptSk<B> for Module<B>
 where
-    Module<B>: GGLWEKeyCompressedEncryptSk<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + SvpPPolBytesOf + VecZnxAutomorphism,
-    Scratch<B>: ScratchAvailable,
+    Module<B>: ModuleN
+        + GGLWEKeyCompressedEncryptSk<B>
+        + VecZnxNormalizeTmpBytes
+        + VecZnxDftBytesOf
+        + SvpPPolBytesOf
+        + VecZnxAutomorphism
+        + SvpPPolAlloc<B>,
+    Scratch<B>: ScratchAvailable + ScratchTakeBasic + ScratchTakeCore<B>,
 {
     fn gglwe_automorphism_key_compressed_encrypt_sk<R, S>(
         &self,
@@ -70,7 +77,7 @@ where
             )
         }
 
-        let (mut sk_out, scratch_1) = scratch.take_glwe_secret(sk.n(), sk.rank());
+        let (mut sk_out, scratch_1) = scratch.take_glwe_secret(self, sk.rank());
 
         {
             (0..res.rank_out().into()).for_each(|i| {
diff --git a/poulpy-core/src/encryption/compressed/gglwe_ct.rs b/poulpy-core/src/encryption/compressed/gglwe_ct.rs
index b67dc88..cca081f 100644
--- a/poulpy-core/src/encryption/compressed/gglwe_ct.rs
+++ b/poulpy-core/src/encryption/compressed/gglwe_ct.rs
@@ -1,6 +1,6 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes,
+        ModuleN, ScratchAvailable, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes,
         ZnNormalizeInplace,
     },
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, ScalarZnxToRef, Scratch, ZnxZero},
@@ -8,6 +8,7 @@ use poulpy_hal::{
 };
 
 use crate::{
+    ScratchTakeCore,
     encryption::{SIGMA, glwe_ct::GLWEEncryptSkInternal},
     layouts::{
         GGLWE, GGLWEInfos, LWEInfos,
@@ -60,13 +61,14 @@ pub trait GGLWECompressedEncryptSk<B: Backend> {
 
 impl<B: Backend> GGLWECompressedEncryptSk<B> for Module<B>
 where
-    Module<B>: GLWEEncryptSkInternal<B>
+    Module<B>: ModuleN
+        + GLWEEncryptSkInternal<B>
         + VecZnxNormalizeInplace<B>
         + VecZnxNormalizeTmpBytes
         + VecZnxDftBytesOf
         + VecZnxAddScalarInplace
         + ZnNormalizeInplace<B>,
-    Scratch<B>: ScratchAvailable,
+    Scratch<B>: ScratchAvailable + ScratchTakeCore<B>,
 {
     fn gglwe_compressed_encrypt_sk<R, P, S>(
         &self,
@@ -130,7 +132,7 @@ where
 
         let mut source_xa = Source::new(seed);
 
-        let (mut tmp_pt, scrach_1) = scratch.take_glwe_pt(res);
+        let (mut tmp_pt, scrach_1) = scratch.take_glwe_pt(self, res);
         (0..rank_in).for_each(|col_i| {
             (0..dnum).for_each(|d_i| {
                 // Adds the scalar_znx_pt to the i-th limb of the vec_znx_pt
diff --git a/poulpy-core/src/encryption/compressed/gglwe_ksk.rs b/poulpy-core/src/encryption/compressed/gglwe_ksk.rs
index 93519b9..3dca15f 100644
--- a/poulpy-core/src/encryption/compressed/gglwe_ksk.rs
+++ b/poulpy-core/src/encryption/compressed/gglwe_ksk.rs
@@ -1,10 +1,11 @@
 use poulpy_hal::{
-    api::{ScratchAvailable, SvpPPolBytesOf, SvpPrepare, VecZnxDftBytesOf, VecZnxNormalizeTmpBytes, VecZnxSwitchRing},
+    api::{ModuleN, ScratchAvailable, ScratchTakeBasic, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxDftBytesOf, VecZnxNormalizeTmpBytes, VecZnxSwitchRing},
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, Scratch},
     source::Source,
 };
 
 use crate::{
+    ScratchTakeCore,
     encryption::compressed::gglwe_ct::GGLWECompressedEncryptSk,
     layouts::{
         GGLWE, GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, LWEInfos, RingDegree,
@@ -17,7 +18,7 @@ impl GLWESwitchingKeyCompressed<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolBytesOf,
+        Module<B>: ModuleN + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolBytesOf,
     {
         (GGLWE::encrypt_sk_tmp_bytes(module, infos) | ScalarZnx::bytes_of(module.n(), 1))
             + ScalarZnx::bytes_of(module.n(), infos.rank_in().into())
@@ -59,13 +60,15 @@ pub trait GGLWEKeyCompressedEncryptSk<B: Backend> {
 
 impl<B: Backend> GGLWEKeyCompressedEncryptSk<B> for Module<B>
 where
-    Module<B>: GGLWECompressedEncryptSk<B>
+    Module<B>: ModuleN
+        + GGLWECompressedEncryptSk<B>
         + SvpPPolBytesOf
         + VecZnxNormalizeTmpBytes
         + VecZnxDftBytesOf
         + VecZnxSwitchRing
-        + SvpPrepare<B>,
-    Scratch<B>: ScratchAvailable,
+        + SvpPrepare<B>
+        + SvpPPolAlloc<B>,
+    Scratch<B>: ScratchAvailable + ScratchTakeBasic + ScratchTakeCore<B>,
 {
     fn gglwe_key_compressed_encrypt_sk<R, SI, SO>(
         &self,
@@ -100,7 +103,7 @@ where
 
         let n: usize = sk_in.n().max(sk_out.n()).into();
 
-        let (mut sk_in_tmp, scratch_1) = scratch.take_scalar_znx(n, sk_in.rank().into());
+        let (mut sk_in_tmp, scratch_1) = scratch.take_scalar_znx(self, sk_in.rank().into());
         (0..sk_in.rank().into()).for_each(|i| {
             self.vec_znx_switch_ring(
                 &mut sk_in_tmp.as_vec_znx_mut(),
@@ -110,9 +113,9 @@ where
             );
         });
 
-        let (mut sk_out_tmp, scratch_2) = scratch_1.take_glwe_secret_prepared(RingDegree(n as u32), sk_out.rank());
+        let (mut sk_out_tmp, scratch_2) = scratch_1.take_glwe_secret_prepared(self, sk_out.rank());
         {
-            let (mut tmp, _) = scratch_2.take_scalar_znx(n, 1);
+            let (mut tmp, _) = scratch_2.take_scalar_znx(self, 1);
             (0..sk_out.rank().into()).for_each(|i| {
                 self.vec_znx_switch_ring(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
                 self.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
diff --git a/poulpy-core/src/encryption/compressed/gglwe_tsk.rs b/poulpy-core/src/encryption/compressed/gglwe_tsk.rs
index 2beaa4b..f3086df 100644
--- a/poulpy-core/src/encryption/compressed/gglwe_tsk.rs
+++ b/poulpy-core/src/encryption/compressed/gglwe_tsk.rs
@@ -1,16 +1,18 @@
 use poulpy_hal::{
     api::{
-        SvpApplyDftToDft, SvpPPolBytesOf, SvpPrepare, VecZnxBigBytesOf, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf,
+        ModuleN, ScratchTakeBasic, SvpApplyDftToDft, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxBigBytesOf, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf,
         VecZnxIdftApplyTmpA, VecZnxNormalizeTmpBytes,
     },
+    oep::{SvpPPolAllocBytesImpl, VecZnxBigAllocBytesImpl, VecZnxDftAllocBytesImpl},
     layouts::{Backend, DataMut, DataRef, Module, Scratch},
     source::Source,
 };
 
 use crate::{
+    ScratchTakeCore,
     encryption::compressed::gglwe_ksk::GGLWEKeyCompressedEncryptSk,
     layouts::{
-        GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, LWEInfos, Rank, TensorKey,
+        GetDist, GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, LWEInfos, Rank, TensorKey,
         compressed::{TensorKeyCompressed, TensorKeyCompressedToMut},
     },
 };
@@ -19,7 +21,7 @@ impl TensorKeyCompressed<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + VecZnxBigBytesOf,
+        Module<B>: ModuleN + SvpPPolBytesOf + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + VecZnxBigBytesOf,
     {
         TensorKey::encrypt_sk_tmp_bytes(module, infos)
     }
@@ -35,18 +37,25 @@ pub trait GGLWETensorKeyCompressedEncryptSk<B: Backend> {
         scratch: &mut Scratch<B>,
     ) where
         R: TensorKeyCompressedToMut,
-        S: GLWESecretToRef;
+        S: GLWESecretToRef + GetDist;
 }
 
 impl<B: Backend> GGLWETensorKeyCompressedEncryptSk<B> for Module<B>
 where
-    Module<B>: GGLWEKeyCompressedEncryptSk<B>
+    Module<B>: ModuleN
+        + GGLWEKeyCompressedEncryptSk<B>
         + VecZnxDftApply<B>
         + SvpApplyDftToDft<B>
         + VecZnxIdftApplyTmpA<B>
         + VecZnxBigNormalize<B>
-        + SvpPrepare<B>,
-    Scratch<B>:,
+        + SvpPrepare<B>
+        + SvpPPolAllocBytesImpl<B>
+        + SvpPPolBytesOf
+        + VecZnxDftAllocBytesImpl<B>
+        + VecZnxBigAllocBytesImpl<B>
+        + VecZnxDftBytesOf
+        + VecZnxBigBytesOf,
+    Scratch<B>: ScratchTakeBasic + ScratchTakeCore<B>,
 {
     fn gglwe_tensor_key_encrypt_sk<R, S>(
         &self,
@@ -57,9 +66,13 @@ where
         scratch: &mut Scratch<B>,
     ) where
         R: TensorKeyCompressedToMut,
-        S: GLWESecretToRef,
+        S: GLWESecretToRef + GetDist,
     {
         let res: &mut TensorKeyCompressed<&mut [u8]> = &mut res.to_mut();
+
+        let (mut sk_dft_prep, scratch_1) = scratch.take_glwe_secret_prepared(self, res.rank_out());
+        sk_dft_prep.prepare(self, sk);
+
         let sk: &GLWESecret<&[u8]> = &sk.to_ref();
 
         #[cfg(debug_assertions)]
@@ -68,21 +81,18 @@ where
             assert_eq!(res.n(), sk.n());
         }
 
-        let n: usize = sk.n().into();
+        // let n: usize = sk.n().into();
         let rank: usize = res.rank_out().into();
 
-        let (mut sk_dft_prep, scratch_1) = scratch.take_glwe_secret_prepared(sk.n(), res.rank_out());
-        sk_dft_prep.prepare(self, sk, scratch_1);
-
-        let (mut sk_dft, scratch_2) = scratch_1.take_vec_znx_dft(n, rank, 1);
+        let (mut sk_dft, scratch_2) = scratch_1.take_vec_znx_dft(self, rank, 1);
 
         for i in 0..rank {
             self.vec_znx_dft_apply(1, 0, &mut sk_dft, i, &sk.data.as_vec_znx(), i);
         }
 
-        let (mut sk_ij_big, scratch_3) = scratch_2.take_vec_znx_big(n, 1, 1);
-        let (mut sk_ij, scratch_4) = scratch_3.take_glwe_secret(sk.n(), Rank(1));
-        let (mut sk_ij_dft, scratch_5) = scratch_4.take_vec_znx_dft(n, 1, 1);
+        let (mut sk_ij_big, scratch_3) = scratch_2.take_vec_znx_big(self, 1, 1);
+        let (mut sk_ij, scratch_4) = scratch_3.take_glwe_secret(self, Rank(1));
+        let (mut sk_ij_dft, scratch_5) = scratch_4.take_vec_znx_dft(self, 1, 1);
 
         let mut source_xa: Source = Source::new(seed_xa);
 
@@ -125,6 +135,7 @@ impl<DataSelf: DataMut> TensorKeyCompressed<DataSelf> {
         source_xe: &mut Source,
         scratch: &mut Scratch<B>,
     ) where
+        GLWESecret<DataSk>: GetDist,
         Module<B>: GGLWETensorKeyCompressedEncryptSk<B>,
     {
         module.gglwe_tensor_key_encrypt_sk(self, sk, seed_xa, source_xe, scratch);
diff --git a/poulpy-core/src/encryption/compressed/ggsw_ct.rs b/poulpy-core/src/encryption/compressed/ggsw_ct.rs
index 567f04f..6595e15 100644
--- a/poulpy-core/src/encryption/compressed/ggsw_ct.rs
+++ b/poulpy-core/src/encryption/compressed/ggsw_ct.rs
@@ -1,10 +1,11 @@
 use poulpy_hal::{
-    api::{VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
+    api::{ModuleN, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, ScalarZnxToRef, Scratch, ZnxZero},
     source::Source,
 };
 
 use crate::{
+    ScratchTakeCore,
     encryption::{SIGMA, glwe_ct::GLWEEncryptSkInternal},
     layouts::{
         GGSW, GGSWInfos, GLWEInfos, LWEInfos,
@@ -40,8 +41,8 @@ pub trait GGSWCompressedEncryptSk<B: Backend> {
 
 impl<B: Backend> GGSWCompressedEncryptSk<B> for Module<B>
 where
-    Module<B>: GLWEEncryptSkInternal<B> + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
-    Scratch<B>:,
+    Module<B>: ModuleN + GLWEEncryptSkInternal<B> + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
+    Scratch<B>: ScratchTakeCore<B>,
 {
     fn ggsw_compressed_encrypt_sk<R, P, S>(
         &self,
@@ -74,7 +75,7 @@ where
         let cols: usize = rank + 1;
         let dsize: usize = res.dsize().into();
 
-        let (mut tmp_pt, scratch_1) = scratch.take_glwe_pt(&res.glwe_layout());
+        let (mut tmp_pt, scratch_1) = scratch.take_glwe_pt(self, &res.glwe_layout());
 
         let mut source = Source::new(seed_xa);
 
diff --git a/poulpy-core/src/encryption/gglwe_atk.rs b/poulpy-core/src/encryption/gglwe_atk.rs
index 6536c7e..972e06c 100644
--- a/poulpy-core/src/encryption/gglwe_atk.rs
+++ b/poulpy-core/src/encryption/gglwe_atk.rs
@@ -1,6 +1,6 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
+        ModuleN, ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
         VecZnxAddScalarInplace, VecZnxAutomorphism, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf, VecZnxFillUniform,
         VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubInplace,
         VecZnxSwitchRing,
@@ -9,15 +9,18 @@ use poulpy_hal::{
     source::Source,
 };
 
-use crate::layouts::{
-    AutomorphismKey, AutomorphismKeyToMut, GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, GLWESwitchingKey, LWEInfos,
+use crate::{
+    ScratchTakeCore,
+    layouts::{
+        AutomorphismKey, AutomorphismKeyToMut, GGLWEInfos, GLWEInfos, GLWESecret, GLWESecretToRef, GLWESwitchingKey, LWEInfos,
+    },
 };
 
 impl AutomorphismKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<BE: Backend, A>(module: &Module<BE>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<BE>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
+        Module<BE>: ModuleN + SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolAlloc<BE>,
     {
         assert_eq!(
             infos.rank_in(),
@@ -76,7 +79,8 @@ where
 
 impl<BE: Backend> GGLWEAutomorphismKeyEncryptSk<BE> for Module<BE>
 where
-    Module<BE>: VecZnxAddScalarInplace
+    Module<BE>: ModuleN 
+        + VecZnxAddScalarInplace
         + VecZnxDftBytesOf
         + VecZnxBigNormalize<BE>
         + VecZnxDftApply<BE>
@@ -93,8 +97,10 @@ where
         + SvpPrepare<BE>
         + VecZnxSwitchRing
         + SvpPPolBytesOf
-        + VecZnxAutomorphism,
-    Scratch<BE>: ScratchAvailable,
+        + VecZnxAutomorphism
+        + SvpPPolAlloc<BE>
+        + SvpPPolBytesOf,
+    Scratch<BE>: ScratchAvailable + ScratchTakeCore<BE>,
 {
     fn gglwe_automorphism_key_encrypt_sk<A, B>(
         &self,
@@ -126,7 +132,7 @@ where
             )
         }
 
-        let (mut sk_out, scratch_1) = scratch.take_glwe_secret(sk.n(), sk.rank());
+        let (mut sk_out, scratch_1) = scratch.take_glwe_secret(self, sk.rank());
 
         {
             (0..res.rank_out().into()).for_each(|i| {
diff --git a/poulpy-core/src/encryption/gglwe_ct.rs b/poulpy-core/src/encryption/gglwe_ct.rs
index d333892..d0ab3a0 100644
--- a/poulpy-core/src/encryption/gglwe_ct.rs
+++ b/poulpy-core/src/encryption/gglwe_ct.rs
@@ -1,11 +1,11 @@
 use poulpy_hal::{
-    api::{ScratchAvailable, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
+    api::{ModuleN, ScratchAvailable, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, ScalarZnxToRef, Scratch, ZnxZero},
     source::Source,
 };
 
 use crate::{
-    encryption::glwe_ct::GLWEEncryptSk,
+    encryption::glwe_ct::GLWEEncryptSk, layouts::GLWEInfos, ScratchTakeCore,
     layouts::{
         GGLWE, GGLWEInfos, GGLWEToMut, GLWE, GLWEPlaintext, LWEInfos,
         prepared::{GLWESecretPrepared, GLWESecretPreparedToRef},
@@ -47,8 +47,8 @@ pub trait GGLWEEncryptSk<B: Backend> {
 
 impl<B: Backend> GGLWEEncryptSk<B> for Module<B>
 where
-    Module<B>: GLWEEncryptSk<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
-    Scratch<B>: ScratchAvailable,
+    Module<B>: ModuleN + GLWEEncryptSk<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
+    Scratch<B>: ScratchAvailable + ScratchTakeCore<B>,
 {
     fn gglwe_encrypt_sk<R, P, S>(
         &self,
@@ -111,7 +111,7 @@ where
         let base2k: usize = res.base2k().into();
         let rank_in: usize = res.rank_in().into();
 
-        let (mut tmp_pt, scrach_1) = scratch.take_glwe_pt(res);
+        let (mut tmp_pt, scrach_1) = scratch.take_glwe_pt(self, &res.glwe_layout());
         // For each input column (i.e. rank) produces a GGLWE ciphertext of rank_out+1 columns
         //
         // Example for ksk rank 2 to rank 3:
diff --git a/poulpy-core/src/encryption/gglwe_ksk.rs b/poulpy-core/src/encryption/gglwe_ksk.rs
index ef9b5bf..c825c73 100644
--- a/poulpy-core/src/encryption/gglwe_ksk.rs
+++ b/poulpy-core/src/encryption/gglwe_ksk.rs
@@ -1,22 +1,26 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
+        ModuleN, ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
         VecZnxAddScalarInplace, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf, VecZnxFillUniform, VecZnxIdftApplyConsume,
         VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubInplace, VecZnxSwitchRing,
+        ScratchTakeBasic,
     },
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, Scratch},
     source::Source,
 };
 
-use crate::layouts::{
+use crate::{
+    ScratchTakeCore,
+    layouts::{
     GGLWE, GGLWEInfos, GLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, RingDegree, prepared::GLWESecretPrepared,
+    },
 };
 
 impl GLWESwitchingKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
+        Module<B>: ModuleN + SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolAlloc<B>,
     {
         (GGLWE::encrypt_sk_tmp_bytes(module, infos) | ScalarZnx::bytes_of(module.n(), 1))
             + ScalarZnx::bytes_of(module.n(), infos.rank_in().into())
@@ -42,7 +46,8 @@ impl<DataSelf: DataMut> GLWESwitchingKey<DataSelf> {
         source_xe: &mut Source,
         scratch: &mut Scratch<B>,
     ) where
-        Module<B>: VecZnxAddScalarInplace
+        Module<B>: ModuleN
+            + VecZnxAddScalarInplace
             + VecZnxDftBytesOf
             + VecZnxBigNormalize<B>
             + VecZnxDftApply<B>
@@ -58,8 +63,9 @@ impl<DataSelf: DataMut> GLWESwitchingKey<DataSelf> {
             + VecZnxSub
             + SvpPrepare<B>
             + VecZnxSwitchRing
-            + SvpPPolBytesOf,
-        Scratch<B>: ScratchAvailable,
+            + SvpPPolBytesOf
+            + SvpPPolAlloc<B>,
+        Scratch<B>: ScratchAvailable + ScratchTakeBasic + ScratchTakeCore<B>,
     {
         #[cfg(debug_assertions)]
         {
@@ -75,7 +81,7 @@ impl<DataSelf: DataMut> GLWESwitchingKey<DataSelf> {
 
         let n: usize = sk_in.n().max(sk_out.n()).into();
 
-        let (mut sk_in_tmp, scratch_1) = scratch.take_scalar_znx(n, sk_in.rank().into());
+        let (mut sk_in_tmp, scratch_1) = scratch.take_scalar_znx(module, sk_in.rank().into());
         (0..sk_in.rank().into()).for_each(|i| {
             module.vec_znx_switch_ring(
                 &mut sk_in_tmp.as_vec_znx_mut(),
@@ -85,9 +91,9 @@ impl<DataSelf: DataMut> GLWESwitchingKey<DataSelf> {
             );
         });
 
-        let (mut sk_out_tmp, scratch_2) = scratch_1.take_glwe_secret_prepared(RingDegree(n as u32), sk_out.rank());
+        let (mut sk_out_tmp, scratch_2) = scratch_1.take_glwe_secret_prepared(module, sk_out.rank());
         {
-            let (mut tmp, _) = scratch_2.take_scalar_znx(n, 1);
+            let (mut tmp, _) = scratch_2.take_scalar_znx(module, 1);
             (0..sk_out.rank().into()).for_each(|i| {
                 module.vec_znx_switch_ring(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
                 module.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
diff --git a/poulpy-core/src/encryption/gglwe_tsk.rs b/poulpy-core/src/encryption/gglwe_tsk.rs
index 62d1a15..918eb8a 100644
--- a/poulpy-core/src/encryption/gglwe_tsk.rs
+++ b/poulpy-core/src/encryption/gglwe_tsk.rs
@@ -1,29 +1,33 @@
 use poulpy_hal::{
     api::{
-        SvpApplyDftToDft, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
+        ModuleN, ScratchTakeBasic, SvpApplyDftToDft, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
         VecZnxAddScalarInplace, VecZnxBigBytesOf, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf, VecZnxFillUniform,
         VecZnxIdftApplyConsume, VecZnxIdftApplyTmpA, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub,
         VecZnxSubInplace, VecZnxSwitchRing,
     },
     layouts::{Backend, DataMut, DataRef, Module, Scratch},
+    oep::VecZnxBigAllocBytesImpl,
     source::Source,
 };
 
-use crate::layouts::{
-    GGLWEInfos, GLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, Rank, RingDegree, TensorKey, prepared::GLWESecretPrepared,
+use crate::{
+    ScratchTakeCore,
+    layouts::{
+        GetDist, GGLWEInfos, GLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, Rank, TensorKey, prepared::GLWESecretPrepared,
+    },
 };
 
 impl TensorKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + VecZnxBigBytesOf,
+        Module<B>: ModuleN + SvpPPolBytesOf + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + VecZnxBigBytesOf,
     {
         GLWESecretPrepared::bytes_of(module, infos.rank_out())
             + module.bytes_of_vec_znx_dft(infos.rank_out().into(), 1)
             + module.bytes_of_vec_znx_big(1, 1)
             + module.bytes_of_vec_znx_dft(1, 1)
-            + GLWESecret::bytes_of(RingDegree(module.n() as u32), Rank(1))
+            + GLWESecret::bytes_of(module, Rank(1))
             + GLWESwitchingKey::encrypt_sk_tmp_bytes(module, infos)
     }
 }
@@ -37,7 +41,9 @@ impl<DataSelf: DataMut> TensorKey<DataSelf> {
         source_xe: &mut Source,
         scratch: &mut Scratch<B>,
     ) where
-        Module<B>: SvpApplyDftToDft<B>
+        GLWESecret<DataSk>: GetDist,
+        Module<B>: ModuleN
+            + SvpApplyDftToDft<B>
             + VecZnxIdftApplyTmpA<B>
             + VecZnxAddScalarInplace
             + VecZnxDftBytesOf
@@ -55,8 +61,11 @@ impl<DataSelf: DataMut> TensorKey<DataSelf> {
             + VecZnxSub
             + SvpPrepare<B>
             + VecZnxSwitchRing
-            + SvpPPolBytesOf,
-        Scratch<B>:,
+            + SvpPPolBytesOf
+            + VecZnxBigAllocBytesImpl<B>
+            + VecZnxBigBytesOf
+            + SvpPPolAlloc<B>,
+        Scratch<B>: ScratchTakeBasic + ScratchTakeCore<B>,
     {
         #[cfg(debug_assertions)]
         {
@@ -64,21 +73,21 @@ impl<DataSelf: DataMut> TensorKey<DataSelf> {
             assert_eq!(self.n(), sk.n());
         }
 
-        let n: RingDegree = sk.n();
+        // let n: RingDegree = sk.n();
         let rank: Rank = self.rank_out();
 
-        let (mut sk_dft_prep, scratch_1) = scratch.take_glwe_secret_prepared(n, rank);
-        sk_dft_prep.prepare(module, sk, scratch_1);
+        let (mut sk_dft_prep, scratch_1) = scratch.take_glwe_secret_prepared(module, rank);
+        sk_dft_prep.prepare(module, sk);
 
-        let (mut sk_dft, scratch_2) = scratch_1.take_vec_znx_dft(n.into(), rank.into(), 1);
+        let (mut sk_dft, scratch_2) = scratch_1.take_vec_znx_dft(module, rank.into(), 1);
 
         (0..rank.into()).for_each(|i| {
             module.vec_znx_dft_apply(1, 0, &mut sk_dft, i, &sk.data.as_vec_znx(), i);
         });
 
-        let (mut sk_ij_big, scratch_3) = scratch_2.take_vec_znx_big(n.into(), 1, 1);
-        let (mut sk_ij, scratch_4) = scratch_3.take_glwe_secret(n, Rank(1));
-        let (mut sk_ij_dft, scratch_5) = scratch_4.take_vec_znx_dft(n.into(), 1, 1);
+        let (mut sk_ij_big, scratch_3) = scratch_2.take_vec_znx_big(module, 1, 1);
+        let (mut sk_ij, scratch_4) = scratch_3.take_glwe_secret(module, Rank(1));
+        let (mut sk_ij_dft, scratch_5) = scratch_4.take_vec_znx_dft(module, 1, 1);
 
         (0..rank.into()).for_each(|i| {
             (i..rank.into()).for_each(|j| {
diff --git a/poulpy-core/src/encryption/ggsw_ct.rs b/poulpy-core/src/encryption/ggsw_ct.rs
index b044ae3..3357380 100644
--- a/poulpy-core/src/encryption/ggsw_ct.rs
+++ b/poulpy-core/src/encryption/ggsw_ct.rs
@@ -1,11 +1,11 @@
 use poulpy_hal::{
-    api::{VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
+    api::{ModuleN, VecZnxAddScalarInplace, VecZnxDftBytesOf, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes},
     layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, ScalarZnxToRef, Scratch, VecZnx, ZnxZero},
     source::Source,
 };
 
 use crate::{
-    SIGMA,
+    SIGMA, ScratchTakeCore,
     encryption::glwe_ct::GLWEEncryptSkInternal,
     layouts::{
         GGSW, GGSWInfos, GGSWToMut, GLWE, GLWEInfos, LWEInfos,
@@ -44,8 +44,8 @@ pub trait GGSWEncryptSk<B: Backend> {
 
 impl<B: Backend> GGSWEncryptSk<B> for Module<B>
 where
-    Module<B>: GLWEEncryptSkInternal<B> + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
-    Scratch<B>:,
+    Module<B>: ModuleN + GLWEEncryptSkInternal<B> + VecZnxAddScalarInplace + VecZnxNormalizeInplace<B>,
+    Scratch<B>: ScratchTakeCore<B>,
 {
     fn ggsw_encrypt_sk<R, P, S>(
         &self,
@@ -80,7 +80,7 @@ where
         let dsize: usize = res.dsize().into();
         let cols: usize = (rank + 1).into();
 
-        let (mut tmp_pt, scratch_1) = scratch.take_glwe_pt(&res.glwe_layout());
+        let (mut tmp_pt, scratch_1) = scratch.take_glwe_pt(self, &res.glwe_layout());
 
         for row_i in 0..res.dnum().into() {
             tmp_pt.data.zero();
diff --git a/poulpy-core/src/encryption/glwe_ct.rs b/poulpy-core/src/encryption/glwe_ct.rs
index 16bbadf..fa314d5 100644
--- a/poulpy-core/src/encryption/glwe_ct.rs
+++ b/poulpy-core/src/encryption/glwe_ct.rs
@@ -1,9 +1,9 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, SvpApplyDftToDft, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace,
+        ModuleN, ScratchAvailable, SvpApplyDftToDft, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace,
         VecZnxAddNormal, VecZnxBigAddNormal, VecZnxBigAddSmallInplace, VecZnxBigBytesOf, VecZnxBigNormalize, VecZnxDftApply,
         VecZnxDftBytesOf, VecZnxFillUniform, VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace,
-        VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubInplace,
+        VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubInplace, ScratchTakeBasic,
     },
     layouts::{Backend, DataMut, Module, ScalarZnx, Scratch, VecZnx, VecZnxBig, VecZnxToMut, ZnxInfos, ZnxZero},
     source::Source,
@@ -19,19 +19,19 @@ use crate::{
 };
 
 impl GLWE<Vec<u8>> {
-    pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
+    pub fn encrypt_sk_tmp_bytes<BE: Backend, A>(module: &Module<BE>, infos: &A) -> usize
     where
         A: GLWEInfos,
-        Module<B>: VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
+        Module<BE>: VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
     {
         let size: usize = infos.size();
         assert_eq!(module.n() as u32, infos.n());
         module.vec_znx_normalize_tmp_bytes() + 2 * VecZnx::bytes_of(module.n(), 1, size) + module.bytes_of_vec_znx_dft(1, size)
     }
-    pub fn encrypt_pk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
+    pub fn encrypt_pk_tmp_bytes<BE: Backend, A>(module: &Module<BE>, infos: &A) -> usize
     where
         A: GLWEInfos,
-        Module<B>: VecZnxDftBytesOf + SvpPPolBytesOf + VecZnxBigBytesOf + VecZnxNormalizeTmpBytes,
+        Module<BE>: VecZnxDftBytesOf + SvpPPolBytesOf + VecZnxBigBytesOf + VecZnxNormalizeTmpBytes,
     {
         let size: usize = infos.size();
         assert_eq!(module.n() as u32, infos.n());
@@ -42,68 +42,68 @@ impl GLWE<Vec<u8>> {
 }
 
 impl<D: DataMut> GLWE<D> {
-    pub fn encrypt_sk<R, P, S, B: Backend>(
+    pub fn encrypt_sk<R, P, S, BE: Backend>(
         &mut self,
-        module: &Module<B>,
+        module: &Module<BE>,
         pt: &P,
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         P: GLWEPlaintextToRef,
-        S: GLWESecretPreparedToRef<B>,
-        Module<B>: GLWEEncryptSk<B>,
+        S: GLWESecretPreparedToRef<BE>,
+        Module<BE>: GLWEEncryptSk<BE>,
     {
         module.glwe_encrypt_sk(self, pt, sk, source_xa, source_xe, scratch);
     }
 
-    pub fn encrypt_zero_sk<S, B: Backend>(
+    pub fn encrypt_zero_sk<S, BE: Backend>(
         &mut self,
-        module: &Module<B>,
+        module: &Module<BE>,
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
-        S: GLWESecretPreparedToRef<B>,
-        Module<B>: GLWEEncryptZeroSk<B>,
+        S: GLWESecretPreparedToRef<BE>,
+        Module<BE>: GLWEEncryptZeroSk<BE>,
     {
         module.glwe_encrypt_zero_sk(self, sk, source_xa, source_xe, scratch);
     }
 
-    pub fn encrypt_pk<P, K, B: Backend>(
+    pub fn encrypt_pk<P, K, BE: Backend>(
         &mut self,
-        module: &Module<B>,
+        module: &Module<BE>,
         pt: &P,
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         P: GLWEPlaintextToRef,
-        K: GLWEPublicKeyPreparedToRef<B>,
-        Module<B>: GLWEEncryptPk<B>,
+        K: GLWEPublicKeyPreparedToRef<BE>,
+        Module<BE>: GLWEEncryptPk<BE>,
     {
         module.glwe_encrypt_pk(self, pt, pk, source_xu, source_xe, scratch);
     }
 
-    pub fn encrypt_zero_pk<K, B: Backend>(
+    pub fn encrypt_zero_pk<K, BE: Backend>(
         &mut self,
-        module: &Module<B>,
+        module: &Module<BE>,
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
-        K: GLWEPublicKeyPreparedToRef<B>,
-        Module<B>: GLWEEncryptZeroPk<B>,
+        K: GLWEPublicKeyPreparedToRef<BE>,
+        Module<BE>: GLWEEncryptZeroPk<BE>,
     {
         module.glwe_encrypt_zero_pk(self, pk, source_xu, source_xe, scratch);
     }
 }
 
-pub trait GLWEEncryptSk<B: Backend> {
+pub trait GLWEEncryptSk<BE: Backend> {
     fn glwe_encrypt_sk<R, P, S>(
         &self,
         res: &mut R,
@@ -111,17 +111,17 @@ pub trait GLWEEncryptSk<B: Backend> {
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        S: GLWESecretPreparedToRef<B>;
+        S: GLWESecretPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptSk<B> for Module<B>
+impl<BE: Backend> GLWEEncryptSk<BE> for Module<BE>
 where
-    Module<B>: GLWEEncryptSkInternal<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
-    Scratch<B>: ScratchAvailable,
+    Module<BE>: GLWEEncryptSkInternal<BE> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
+    Scratch<BE>: ScratchAvailable,
 {
     fn glwe_encrypt_sk<R, P, S>(
         &self,
@@ -130,18 +130,18 @@ where
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        S: GLWESecretPreparedToRef<B>,
+        S: GLWESecretPreparedToRef<BE>,
     {
         let mut res: GLWE<&mut [u8]> = res.to_mut();
         let pt: GLWEPlaintext<&[u8]> = pt.to_ref();
 
         #[cfg(debug_assertions)]
         {
-            let sk: GLWESecretPrepared<&[u8], B> = sk.to_ref();
+            let sk: GLWESecretPrepared<&[u8], BE> = sk.to_ref();
             assert_eq!(res.rank(), sk.rank());
             assert_eq!(res.n(), self.n() as u32);
             assert_eq!(sk.n(), self.n() as u32);
@@ -171,23 +171,23 @@ where
     }
 }
 
-pub trait GLWEEncryptZeroSk<B: Backend> {
+pub trait GLWEEncryptZeroSk<BE: Backend> {
     fn glwe_encrypt_zero_sk<R, S>(
         &self,
         res: &mut R,
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
-        S: GLWESecretPreparedToRef<B>;
+        S: GLWESecretPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptZeroSk<B> for Module<B>
+impl<BE: Backend> GLWEEncryptZeroSk<BE> for Module<BE>
 where
-    Module<B>: GLWEEncryptSkInternal<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
-    Scratch<B>: ScratchAvailable,
+    Module<BE>: GLWEEncryptSkInternal<BE> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf,
+    Scratch<BE>: ScratchAvailable,
 {
     fn glwe_encrypt_zero_sk<R, S>(
         &self,
@@ -195,16 +195,16 @@ where
         sk: &S,
         source_xa: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
-        S: GLWESecretPreparedToRef<B>,
+        S: GLWESecretPreparedToRef<BE>,
     {
         let mut res: GLWE<&mut [u8]> = res.to_mut();
 
         #[cfg(debug_assertions)]
         {
-            let sk: GLWESecretPrepared<&[u8], B> = sk.to_ref();
+            let sk: GLWESecretPrepared<&[u8], BE> = sk.to_ref();
             assert_eq!(res.rank(), sk.rank());
             assert_eq!(res.n(), self.n() as u32);
             assert_eq!(sk.n(), self.n() as u32);
@@ -233,7 +233,7 @@ where
     }
 }
 
-pub trait GLWEEncryptPk<B: Backend> {
+pub trait GLWEEncryptPk<BE: Backend> {
     fn glwe_encrypt_pk<R, P, K>(
         &self,
         res: &mut R,
@@ -241,16 +241,16 @@ pub trait GLWEEncryptPk<B: Backend> {
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        K: GLWEPublicKeyPreparedToRef<B>;
+        K: GLWEPublicKeyPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptPk<B> for Module<B>
+impl<BE: Backend> GLWEEncryptPk<BE> for Module<BE>
 where
-    Module<B>: GLWEEncryptPkInternal<B>,
+    Module<BE>: GLWEEncryptPkInternal<BE>,
 {
     fn glwe_encrypt_pk<R, P, K>(
         &self,
@@ -259,32 +259,32 @@ where
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        K: GLWEPublicKeyPreparedToRef<B>,
+        K: GLWEPublicKeyPreparedToRef<BE>,
     {
         self.glwe_encrypt_pk_internal(res, Some((pt, 0)), pk, source_xu, source_xe, scratch);
     }
 }
 
-pub trait GLWEEncryptZeroPk<B: Backend> {
+pub trait GLWEEncryptZeroPk<BE: Backend> {
     fn glwe_encrypt_zero_pk<R, K>(
         &self,
         res: &mut R,
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
-        K: GLWEPublicKeyPreparedToRef<B>;
+        K: GLWEPublicKeyPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptZeroPk<B> for Module<B>
+impl<BE: Backend> GLWEEncryptZeroPk<BE> for Module<BE>
 where
-    Module<B>: GLWEEncryptPkInternal<B>,
+    Module<BE>: GLWEEncryptPkInternal<BE>,
 {
     fn glwe_encrypt_zero_pk<R, K>(
         &self,
@@ -292,10 +292,10 @@ where
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
-        K: GLWEPublicKeyPreparedToRef<B>,
+        K: GLWEPublicKeyPreparedToRef<BE>,
     {
         self.glwe_encrypt_pk_internal(
             res,
@@ -308,7 +308,7 @@ where
     }
 }
 
-pub(crate) trait GLWEEncryptPkInternal<B: Backend> {
+pub(crate) trait GLWEEncryptPkInternal<BE: Backend> {
     fn glwe_encrypt_pk_internal<R, P, K>(
         &self,
         res: &mut R,
@@ -316,22 +316,25 @@ pub(crate) trait GLWEEncryptPkInternal<B: Backend> {
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        K: GLWEPublicKeyPreparedToRef<B>;
+        K: GLWEPublicKeyPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptPkInternal<B> for Module<B>
+impl<BE: Backend> GLWEEncryptPkInternal<BE> for Module<BE>
 where
-    Module<B>: SvpPrepare<B>
-        + SvpApplyDftToDft<B>
-        + VecZnxIdftApplyConsume<B>
-        + VecZnxBigAddNormal<B>
-        + VecZnxBigAddSmallInplace<B>
-        + VecZnxBigNormalize<B>,
-    Scratch<B>:,
+    Module<BE>: SvpPrepare<BE>
+        + SvpApplyDftToDft<BE>
+        + VecZnxIdftApplyConsume<BE>
+        + VecZnxBigAddNormal<BE>
+        + VecZnxBigAddSmallInplace<BE>
+        + VecZnxBigNormalize<BE>
+        + SvpPPolBytesOf
+        + ModuleN
+        + VecZnxDftBytesOf,
+    Scratch<BE>: ScratchTakeBasic,
 {
     fn glwe_encrypt_pk_internal<R, P, K>(
         &self,
@@ -340,14 +343,14 @@ where
         pk: &K,
         source_xu: &mut Source,
         source_xe: &mut Source,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: GLWEToMut,
         P: GLWEPlaintextToRef,
-        K: GLWEPublicKeyPreparedToRef<B>,
+        K: GLWEPublicKeyPreparedToRef<BE>,
     {
         let res: &mut GLWE<&mut [u8]> = &mut res.to_mut();
-        let pk: &GLWEPublicKeyPrepared<&[u8], B> = &pk.to_ref();
+        let pk: &GLWEPublicKeyPrepared<&[u8], BE> = &pk.to_ref();
 
         #[cfg(debug_assertions)]
         {
@@ -365,10 +368,10 @@ where
         let cols: usize = (res.rank() + 1).into();
 
         // Generates u according to the underlying secret distribution.
-        let (mut u_dft, scratch_1) = scratch.take_svp_ppol(res.n().into(), 1);
+        let (mut u_dft, scratch_1) = scratch.take_svp_ppol(self, 1);
 
         {
-            let (mut u, _) = scratch_1.take_scalar_znx(res.n().into(), 1);
+            let (mut u, _) = scratch_1.take_scalar_znx(self, 1);
             match pk.dist {
                 Distribution::NONE => panic!(
                     "invalid public key: SecretDistribution::NONE, ensure it has been correctly intialized through \
@@ -387,7 +390,7 @@ where
 
         // ct[i] = pk[i] * u + ei (+ m if col = i)
         (0..cols).for_each(|i| {
-            let (mut ci_dft, scratch_2) = scratch_1.take_vec_znx_dft(res.n().into(), 1, size_pk);
+            let (mut ci_dft, scratch_2) = scratch_1.take_vec_znx_dft(self, 1, size_pk);
             // ci_dft = DFT(u) * DFT(pk[i])
             self.svp_apply_dft_to_dft(&mut ci_dft, 0, &u_dft, 0, &pk.data, i);
 
@@ -418,7 +421,7 @@ where
     }
 }
 
-pub(crate) trait GLWEEncryptSkInternal<B: Backend> {
+pub(crate) trait GLWEEncryptSkInternal<BE: Backend> {
     fn glwe_encrypt_sk_internal<R, P, S>(
         &self,
         base2k: usize,
@@ -431,29 +434,30 @@ pub(crate) trait GLWEEncryptSkInternal<B: Backend> {
         source_xa: &mut Source,
         source_xe: &mut Source,
         sigma: f64,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: VecZnxToMut,
         P: GLWEPlaintextToRef,
-        S: GLWESecretPreparedToRef<B>;
+        S: GLWESecretPreparedToRef<BE>;
 }
 
-impl<B: Backend> GLWEEncryptSkInternal<B> for Module<B>
+impl<BE: Backend> GLWEEncryptSkInternal<BE> for Module<BE>
 where
-    Module<B>: VecZnxDftBytesOf
-        + VecZnxBigNormalize<B>
-        + VecZnxDftApply<B>
-        + SvpApplyDftToDftInplace<B>
-        + VecZnxIdftApplyConsume<B>
+    Module<BE>: ModuleN
+        + VecZnxDftBytesOf
+        + VecZnxBigNormalize<BE>
+        + VecZnxDftApply<BE>
+        + SvpApplyDftToDftInplace<BE>
+        + VecZnxIdftApplyConsume<BE>
         + VecZnxNormalizeTmpBytes
         + VecZnxFillUniform
         + VecZnxSubInplace
         + VecZnxAddInplace
-        + VecZnxNormalizeInplace<B>
+        + VecZnxNormalizeInplace<BE>
         + VecZnxAddNormal
-        + VecZnxNormalize<B>
+        + VecZnxNormalize<BE>
         + VecZnxSub,
-    Scratch<B>: ScratchAvailable,
+    Scratch<BE>: ScratchAvailable + ScratchTakeBasic,
 {
     fn glwe_encrypt_sk_internal<R, P, S>(
         &self,
@@ -467,14 +471,14 @@ where
         source_xa: &mut Source,
         source_xe: &mut Source,
         sigma: f64,
-        scratch: &mut Scratch<B>,
+        scratch: &mut Scratch<BE>,
     ) where
         R: VecZnxToMut,
         P: GLWEPlaintextToRef,
-        S: GLWESecretPreparedToRef<B>,
+        S: GLWESecretPreparedToRef<BE>,
     {
         let ct: &mut VecZnx<&mut [u8]> = &mut res.to_mut();
-        let sk: GLWESecretPrepared<&[u8], B> = sk.to_ref();
+        let sk: GLWESecretPrepared<&[u8], BE> = sk.to_ref();
 
         #[cfg(debug_assertions)]
         {
@@ -490,11 +494,11 @@ where
 
         let size: usize = ct.size();
 
-        let (mut c0, scratch_1) = scratch.take_vec_znx(ct.n(), 1, size);
+        let (mut c0, scratch_1) = scratch.take_vec_znx(self, 1, size);
         c0.zero();
 
         {
-            let (mut ci, scratch_2) = scratch_1.take_vec_znx(ct.n(), 1, size);
+            let (mut ci, scratch_2) = scratch_1.take_vec_znx(self, 1, size);
 
             // ct[i] = uniform
             // ct[0] -= c[i] * s[i],
@@ -504,7 +508,7 @@ where
                 // ct[i] = uniform (+ pt)
                 self.vec_znx_fill_uniform(base2k, ct, col_ct, source_xa);
 
-                let (mut ci_dft, scratch_3) = scratch_2.take_vec_znx_dft(ct.n(), 1, size);
+                let (mut ci_dft, scratch_3) = scratch_2.take_vec_znx_dft(self, 1, size);
 
                 // ci = ct[i] - pt
                 // i.e. we act as we sample ct[i] already as uniform + pt
@@ -522,7 +526,7 @@ where
                 }
 
                 self.svp_apply_dft_to_dft_inplace(&mut ci_dft, 0, &sk.data, i - 1);
-                let ci_big: VecZnxBig<&mut [u8], B> = self.vec_znx_idft_apply_consume(ci_dft);
+                let ci_big: VecZnxBig<&mut [u8], BE> = self.vec_znx_idft_apply_consume(ci_dft);
 
                 // use c[0] as buffer, which is overwritten later by the normalization step
                 self.vec_znx_big_normalize(base2k, &mut ci, 0, base2k, &ci_big, 0, scratch_3);
diff --git a/poulpy-core/src/encryption/glwe_pk.rs b/poulpy-core/src/encryption/glwe_pk.rs
index d89f515..9073cfe 100644
--- a/poulpy-core/src/encryption/glwe_pk.rs
+++ b/poulpy-core/src/encryption/glwe_pk.rs
@@ -47,7 +47,7 @@ where
         // Its ok to allocate scratch space here since pk is usually generated only once.
         let mut scratch: ScratchOwned<B> = ScratchOwned::alloc(GLWE::encrypt_sk_tmp_bytes(self, res));
 
-        let mut tmp: GLWE<Vec<u8>> = GLWE::alloc_from_infos(res);
+        let mut tmp: GLWE<Vec<u8>> = GLWE::alloc_from_infos(self, res);
 
         tmp.encrypt_zero_sk(self, sk, source_xa, source_xe, scratch.borrow());
         res.dist = sk.dist;
diff --git a/poulpy-core/src/encryption/glwe_to_lwe_ksk.rs b/poulpy-core/src/encryption/glwe_to_lwe_ksk.rs
index 971766e..cd3ffec 100644
--- a/poulpy-core/src/encryption/glwe_to_lwe_ksk.rs
+++ b/poulpy-core/src/encryption/glwe_to_lwe_ksk.rs
@@ -1,6 +1,6 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
+        ModuleN, ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
         VecZnxAddScalarInplace, VecZnxAutomorphismInplace, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf,
         VecZnxFillUniform, VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub,
         VecZnxSubInplace, VecZnxSwitchRing,
@@ -9,18 +9,22 @@ use poulpy_hal::{
     source::Source,
 };
 
-use crate::layouts::{
-    GGLWEInfos, GLWESecret, GLWESwitchingKey, GLWEToLWESwitchingKey, LWEInfos, LWESecret, Rank, prepared::GLWESecretPrepared,
+use crate::{
+    ScratchTakeCore,
+    layouts::{
+        GGLWEInfos, GLWESecret, GLWESwitchingKey, GLWEToLWESwitchingKey, LWEInfos, LWESecret, Rank,
+        prepared::GLWESecretPrepared,
+    },
 };
 
 impl GLWEToLWESwitchingKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
+        Module<B>: ModuleN + SvpPPolBytesOf + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
     {
         GLWESecretPrepared::bytes_of(module, infos.rank_in())
-            + (GLWESwitchingKey::encrypt_sk_tmp_bytes(module, infos) | GLWESecret::bytes_of(infos.n(), infos.rank_in()))
+            + (GLWESwitchingKey::encrypt_sk_tmp_bytes(module, infos) | GLWESecret::bytes_of(module, infos.rank_in()))
     }
 }
 
@@ -37,7 +41,8 @@ impl<D: DataMut> GLWEToLWESwitchingKey<D> {
     ) where
         DLwe: DataRef,
         DGlwe: DataRef,
-        Module<B>: VecZnxAutomorphismInplace<B>
+        Module<B>: ModuleN
+            + VecZnxAutomorphismInplace<B>
             + VecZnxAddScalarInplace
             + VecZnxDftBytesOf
             + VecZnxBigNormalize<B>
@@ -54,15 +59,16 @@ impl<D: DataMut> GLWEToLWESwitchingKey<D> {
             + VecZnxSub
             + SvpPrepare<B>
             + VecZnxSwitchRing
-            + SvpPPolBytesOf,
-        Scratch<B>: ScratchAvailable,
+            + SvpPPolBytesOf
+            + SvpPPolAlloc<B>,
+        Scratch<B>: ScratchAvailable + ScratchTakeCore<B>,
     {
         #[cfg(debug_assertions)]
         {
             assert!(sk_lwe.n().0 <= module.n() as u32);
         }
 
-        let (mut sk_lwe_as_glwe, scratch_1) = scratch.take_glwe_secret(sk_glwe.n(), Rank(1));
+        let (mut sk_lwe_as_glwe, scratch_1) = scratch.take_glwe_secret(module, Rank(1));
         sk_lwe_as_glwe.data.zero();
         sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n().into()].copy_from_slice(sk_lwe.data.at(0, 0));
         module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0, scratch_1);
diff --git a/poulpy-core/src/encryption/lwe_ct.rs b/poulpy-core/src/encryption/lwe_ct.rs
index a01d95f..5a743eb 100644
--- a/poulpy-core/src/encryption/lwe_ct.rs
+++ b/poulpy-core/src/encryption/lwe_ct.rs
@@ -1,64 +1,79 @@
 use poulpy_hal::{
     api::{ScratchOwnedAlloc, ScratchOwnedBorrow, ZnAddNormal, ZnFillUniform, ZnNormalizeInplace},
-    layouts::{Backend, DataMut, DataRef, Module, ScratchOwned, Zn, ZnxView, ZnxViewMut},
+    layouts::{Backend, DataMut, Module, ScratchOwned, Zn, ZnxView, ZnxViewMut},
     oep::{ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl},
     source::Source,
 };
 
 use crate::{
     encryption::{SIGMA, SIGMA_BOUND},
-    layouts::{LWE, LWEInfos, LWEPlaintext, LWESecret},
+    layouts::{LWE, LWEInfos, LWEPlaintext, LWESecret, LWEToMut, LWEPlaintextToRef, LWESecretToRef},
 };
 
 impl<DataSelf: DataMut> LWE<DataSelf> {
-    pub fn encrypt_sk<DataPt, DataSk, B>(
-        &mut self,
-        module: &Module<B>,
-        pt: &LWEPlaintext<DataPt>,
-        sk: &LWESecret<DataSk>,
-        source_xa: &mut Source,
-        source_xe: &mut Source,
-    ) where
-        DataPt: DataRef,
-        DataSk: DataRef,
-        Module<B>: ZnFillUniform + ZnAddNormal + ZnNormalizeInplace<B>,
-        B: Backend + ScratchOwnedAllocImpl<B> + ScratchOwnedBorrowImpl<B>,
+
+    pub fn encrypt_sk<P, S, M, BE: Backend>(&mut self, module: &M, pt: &P, sk: &S, source_xa: &mut Source, source_xe: &mut Source)
+    where
+        P: LWEPlaintextToRef,
+        S: LWESecretToRef,
+        M: LWEEncryptSk<BE>,
+        BE: Backend + ScratchOwnedAllocImpl<BE> + ScratchOwnedBorrowImpl<BE>,
     {
+        module.lwe_encrypt_sk(self, pt, sk, source_xa, source_xe);
+    }
+}
+
+
+pub trait LWEEncryptSk<BE: Backend>
+where
+    Self: Sized + ZnFillUniform + ZnAddNormal + ZnNormalizeInplace<BE>,
+{
+    fn lwe_encrypt_sk<R, P, S>(&self, res: &mut R, pt: &P, sk: &S, source_xa: &mut Source, source_xe: &mut Source)
+    where
+        R: LWEToMut,
+        P: LWEPlaintextToRef,
+        S: LWESecretToRef,
+        BE: Backend + ScratchOwnedAllocImpl<BE> + ScratchOwnedBorrowImpl<BE>,
+    {
+        let res: &mut LWE<&mut [u8]> = &mut res.to_mut();
+        let pt: &LWEPlaintext<&[u8]> = &pt.to_ref();
+        let sk: &LWESecret<&[u8]> = &sk.to_ref();
+
         #[cfg(debug_assertions)]
         {
-            assert_eq!(self.n(), sk.n())
+            assert_eq!(res.n(), sk.n())
         }
 
-        let base2k: usize = self.base2k().into();
-        let k: usize = self.k().into();
+        let base2k: usize = res.base2k().into();
+        let k: usize = res.k().into();
 
-        module.zn_fill_uniform((self.n() + 1).into(), base2k, &mut self.data, 0, source_xa);
+        self.zn_fill_uniform((res.n() + 1).into(), base2k, &mut res.data, 0, source_xa);
 
-        let mut tmp_znx: Zn<Vec<u8>> = Zn::alloc(1, 1, self.size());
+        let mut tmp_znx: Zn<Vec<u8>> = Zn::alloc(1, 1, res.size());
 
-        let min_size = self.size().min(pt.size());
+        let min_size = res.size().min(pt.size());
 
         (0..min_size).for_each(|i| {
             tmp_znx.at_mut(0, i)[0] = pt.data.at(0, i)[0]
-                - self.data.at(0, i)[1..]
+                - res.data.at(0, i)[1..]
                     .iter()
                     .zip(sk.data.at(0, 0))
                     .map(|(x, y)| x * y)
                     .sum::<i64>();
         });
 
-        (min_size..self.size()).for_each(|i| {
-            tmp_znx.at_mut(0, i)[0] -= self.data.at(0, i)[1..]
+        (min_size..res.size()).for_each(|i| {
+            tmp_znx.at_mut(0, i)[0] -= res.data.at(0, i)[1..]
                 .iter()
                 .zip(sk.data.at(0, 0))
                 .map(|(x, y)| x * y)
                 .sum::<i64>();
         });
 
-        module.zn_add_normal(
+        self.zn_add_normal(
             1,
             base2k,
-            &mut self.data,
+            &mut res.data,
             0,
             k,
             source_xe,
@@ -66,7 +81,7 @@ impl<DataSelf: DataMut> LWE<DataSelf> {
             SIGMA_BOUND,
         );
 
-        module.zn_normalize_inplace(
+        self.zn_normalize_inplace(
             1,
             base2k,
             &mut tmp_znx,
@@ -74,8 +89,13 @@ impl<DataSelf: DataMut> LWE<DataSelf> {
             ScratchOwned::alloc(size_of::<i64>()).borrow(),
         );
 
-        (0..self.size()).for_each(|i| {
-            self.data.at_mut(0, i)[0] = tmp_znx.at(0, i)[0];
-        });
+        (0..res.size()).for_each(|i| {
+            res.data.at_mut(0, i)[0] = tmp_znx.at(0, i)[0];
+        });        
     }
 }
+
+impl<BE: Backend> LWEEncryptSk<BE> for Module<BE> where
+    Self: Sized + ZnFillUniform + ZnAddNormal + ZnNormalizeInplace<BE>,
+{
+}
\ No newline at end of file
diff --git a/poulpy-core/src/encryption/lwe_ksk.rs b/poulpy-core/src/encryption/lwe_ksk.rs
index 2fd60ff..ed1c5d6 100644
--- a/poulpy-core/src/encryption/lwe_ksk.rs
+++ b/poulpy-core/src/encryption/lwe_ksk.rs
@@ -1,6 +1,6 @@
 use poulpy_hal::{
     api::{
-        SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace,
+        ModuleN, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace,
         VecZnxAutomorphismInplace, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf, VecZnxFillUniform,
         VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubInplace,
         VecZnxSwitchRing,
@@ -9,16 +9,19 @@ use poulpy_hal::{
     source::Source,
 };
 
-use crate::layouts::{
-    GGLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, LWESecret, LWESwitchingKey, Rank, RingDegree,
+use crate::{
+    ScratchTakeCore,
+    layouts::{
+    GGLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, LWESecret, LWESwitchingKey, Rank,
     prepared::GLWESecretPrepared,
+    },
 };
 
 impl LWESwitchingKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
+        Module<B>: ModuleN + SvpPPolBytesOf + SvpPPolAlloc<B> + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
     {
         debug_assert_eq!(
             infos.dsize().0,
@@ -35,7 +38,7 @@ impl LWESwitchingKey<Vec<u8>> {
             1,
             "rank_out > 1 is not supported for LWESwitchingKey"
         );
-        GLWESecret::bytes_of(RingDegree(module.n() as u32), Rank(1))
+        GLWESecret::bytes_of(module, Rank(1))
             + GLWESecretPrepared::bytes_of(module, Rank(1))
             + GLWESwitchingKey::encrypt_sk_tmp_bytes(module, infos)
     }
@@ -54,7 +57,8 @@ impl<D: DataMut> LWESwitchingKey<D> {
     ) where
         DIn: DataRef,
         DOut: DataRef,
-        Module<B>: VecZnxAutomorphismInplace<B>
+        Module<B>: ModuleN
+            + VecZnxAutomorphismInplace<B>
             + VecZnxAddScalarInplace
             + VecZnxDftBytesOf
             + VecZnxBigNormalize<B>
@@ -71,8 +75,9 @@ impl<D: DataMut> LWESwitchingKey<D> {
             + VecZnxSub
             + SvpPrepare<B>
             + VecZnxSwitchRing
-            + SvpPPolBytesOf,
-        Scratch<B>:,
+            + SvpPPolBytesOf
+            + SvpPPolAlloc<B>,
+        Scratch<B>: ScratchTakeCore<B>,
     {
         #[cfg(debug_assertions)]
         {
@@ -81,8 +86,8 @@ impl<D: DataMut> LWESwitchingKey<D> {
             assert!(self.n().0 <= module.n() as u32);
         }
 
-        let (mut sk_in_glwe, scratch_1) = scratch.take_glwe_secret(self.n(), Rank(1));
-        let (mut sk_out_glwe, scratch_2) = scratch_1.take_glwe_secret(self.n(), Rank(1));
+        let (mut sk_in_glwe, scratch_1) = scratch.take_glwe_secret(module, Rank(1));
+        let (mut sk_out_glwe, scratch_2) = scratch_1.take_glwe_secret(module, Rank(1));
 
         sk_out_glwe.data.at_mut(0, 0)[..sk_lwe_out.n().into()].copy_from_slice(sk_lwe_out.data.at(0, 0));
         sk_out_glwe.data.at_mut(0, 0)[sk_lwe_out.n().into()..].fill(0);
diff --git a/poulpy-core/src/encryption/lwe_to_glwe_ksk.rs b/poulpy-core/src/encryption/lwe_to_glwe_ksk.rs
index 041c7c4..32c75fc 100644
--- a/poulpy-core/src/encryption/lwe_to_glwe_ksk.rs
+++ b/poulpy-core/src/encryption/lwe_to_glwe_ksk.rs
@@ -1,6 +1,6 @@
 use poulpy_hal::{
     api::{
-        ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
+        ModuleN, ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolAlloc, SvpPPolBytesOf, SvpPrepare, VecZnxAddInplace, VecZnxAddNormal,
         VecZnxAddScalarInplace, VecZnxAutomorphismInplace, VecZnxBigNormalize, VecZnxDftApply, VecZnxDftBytesOf,
         VecZnxFillUniform, VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub,
         VecZnxSubInplace, VecZnxSwitchRing,
@@ -9,13 +9,16 @@ use poulpy_hal::{
     source::Source,
 };
 
-use crate::layouts::{GGLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, LWESecret, LWEToGLWESwitchingKey, Rank, RingDegree};
+use crate::{
+    ScratchTakeCore,
+    layouts::{GGLWEInfos, GLWESecret, GLWESwitchingKey, LWEInfos, LWESecret, LWEToGLWESwitchingKey, Rank},
+};
 
 impl LWEToGLWESwitchingKey<Vec<u8>> {
     pub fn encrypt_sk_tmp_bytes<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
     where
         A: GGLWEInfos,
-        Module<B>: SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes,
+        Module<B>: ModuleN + SvpPPolBytesOf + VecZnxNormalizeTmpBytes + VecZnxDftBytesOf + VecZnxNormalizeTmpBytes + SvpPPolAlloc<B>,
     {
         debug_assert_eq!(
             infos.rank_in(),
@@ -23,7 +26,7 @@ impl LWEToGLWESwitchingKey<Vec<u8>> {
             "rank_in != 1 is not supported for LWEToGLWESwitchingKey"
         );
         GLWESwitchingKey::encrypt_sk_tmp_bytes(module, infos)
-            + GLWESecret::bytes_of(RingDegree(module.n() as u32), infos.rank_in())
+            + GLWESecret::bytes_of(module, infos.rank_in())
     }
 }
 
@@ -40,7 +43,8 @@ impl<D: DataMut> LWEToGLWESwitchingKey<D> {
     ) where
         DLwe: DataRef,
         DGlwe: DataRef,
-        Module<B>: VecZnxAutomorphismInplace<B>
+        Module<B>: ModuleN
+            + VecZnxAutomorphismInplace<B>
             + VecZnxAddScalarInplace
             + VecZnxDftBytesOf
             + VecZnxBigNormalize<B>
@@ -57,8 +61,9 @@ impl<D: DataMut> LWEToGLWESwitchingKey<D> {
             + VecZnxSub
             + SvpPrepare<B>
             + VecZnxSwitchRing
-            + SvpPPolBytesOf,
-        Scratch<B>: ScratchAvailable,
+            + SvpPPolBytesOf
+            + SvpPPolAlloc<B>,
+        Scratch<B>: ScratchAvailable + ScratchTakeCore<B>,
     {
         #[cfg(debug_assertions)]
         {
@@ -67,7 +72,7 @@ impl<D: DataMut> LWEToGLWESwitchingKey<D> {
             assert!(sk_lwe.n().0 <= module.n() as u32);
         }
 
-        let (mut sk_lwe_as_glwe, scratch_1) = scratch.take_glwe_secret(sk_glwe.n(), Rank(1));
+        let (mut sk_lwe_as_glwe, scratch_1) = scratch.take_glwe_secret(module, Rank(1));
         sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n().into()].copy_from_slice(sk_lwe.data.at(0, 0));
         sk_lwe_as_glwe.data.at_mut(0, 0)[sk_lwe.n().into()..].fill(0);
         module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0, scratch_1);